Functional nanoparticles have been widely considered as the building blocks of potential micro- and nano-scale electronic, optoelectronic devices, gas sensors, as well as a wide variety of other electronic devices. The production of nanoparticles by using gas phase is a clean continuous process which can be operated at atmospheric conditions without requiring any vacuum environment or solvent medium. Fabrication of nanoparticle based devices requires an accurate alignment of nanoparticles in specific locations on a device substrate. An effective method to position particles is through the use of electrostatic forces.
For example, it was demonstrated (Barry C. R., Lwin N. Z., Zheng W., Jacobs H. O., Applied Physics Letters, 2003, 83 (26): 5527-5529; Barry C. R., Steward M. G., Lwin N. Z., Jacobs H. O., Nanotechnology, 2003, 14 (10): 1057-1063; and Jacobs H. O., Campbell S. A., Steward M. G., Advanced Materials, 2002, 14 (21): 1553) that charged carbon nanoparticles can be aligned with an electric field on a charge-patterned substrate.
A contact charging method has been developed which employs a metal-coated polymer stamp to form charging patterns on an insulating substrate. In this method, the oppositely charged nanoparticles are attracted and aligned (Fissan H., Kennedy M. K., Krinke T. J., Kruis F. E., Journal of Nanoparticle Research, 2003, 5 (3-4): 299-310; Krinke T. J., Deppert K., Magnusson M. H., Fissan H., Particle & Particle Systems Characterization, 2002, 19 (5): 321-326; and Krinke T. J., Fissan H., Deppert K., Magnusson M. H., Samuelson L., Applied Physics Letters, 2001, 78 (23): 3708-3710).
For 30 nm-sized particles, the best lateral resolution achieved with this method has been about ˜100 nm. However, the gas-phase patterning of nanoparticles on a charge-patterned substrate has many technical shortcomings, including: (i) failure to attain stable patterns causing the change of the deposition pattern during the particle deposition process, (ii) high possibility for damaging the metal-coated polymer stamp during the charging process, as well as (iii) the necessity of using an insulated surface on the substrate which limits its applications especially for metal-semiconductor devices.
Thus, a new and innovative controllable nanoparticle alignment and deposition technique is needed to obviate the disadvantages of prior art methods.